Every regular expression describes regular language Automata Theory by ComputeNow - July 27, 2019July 27, 20190 Every regular expression describes regular language, let R be an arbitrary regular expression over the alphabet Σ. We will prove that the language described by R is a regular language. The proof is by induction on the structure of R. The first base case of induction: Assume that R = ε. The R describes the language of {ε}. In order
Turing Machine Definition Automata Theory by ComputeNow - December 22, 2018December 22, 20180 Definition of a Turing Machine We start with an informal description of a Turing Machine. Such a machine consists of the following: There are k tapes , for some fixed k ≥ 1. Each tape is divided into cells, and is infinite both to the left and to the right. Each cell stores a symbol belonging to a
Regular Language in Automata Thoery Automata Theory by ComputeNow - September 20, 2018September 18, 20180 Regular Languages or Formal Language : A language is regular if it can be expressed in terms of regular expression. Closure Properties of Regular Languages Union : If L1 and If L2 are two regular languages, their union L1 ∪ L2 will also be regular. For example, L1 = {an | n ≥ 0} and
Definition of Pushdown Automata Automata Theory by ComputeNow - August 17, 20180 Definition of Pushdown Automata Pushdown Automata is a finite automata with extra memory called stack which helps Pushdown automata to recognize Context Free Languages. A Pushdown Automata (PDA) can be defined as : Q is the set of states ∑ is the set of input symbols Γ is the set of pushdown symbols
Equivalence of Automata Automata Theory by ComputeNow - August 15, 20180 Equivalence of Automata Two automata A and B are said to be equivalent if both accept exactly the same set of input strings. Formally, if two automata A and B are equivalent then if there is a path from the start state of A to a final state of A labeled
